Method and apparatus for discriminating type of disks positioned on a CD player

ABSTRACT

Disclosed is a CD player that ensures a setup operation and reproduction of information even when a partially recorded CD-R is set therein. The CD player sequentially performs the setup operation, starting from the first setup position located at the innermost periphery of the CD, predetermined for the setup operation, until the setup operation is complete at any of n-th (n=2, 3, . . . ) setup positions lying outwardly of the first setup position. If the setup operation is not completed even at an n-th setup position located at the outermost periphery of the CD, the CD player performs the setup operation again at at least one setup position lying inwardly of the n-th setup position. Also disclosed is a CD player that can discriminate a partially recorded, additionally recordable CD-R, and can execute the reproduction control for the PRD. This CD player discriminates a set disk as an additionally recordable one when a mirror-finished portion is detected in the control to detect the lead-in area or when the lead-in area cannot be detected and the TOC information cannot be read.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a CD (Compact Disk) player, and moreparticularly, to a CD player capable of playing back a partiallyrecorded, additionally recordable CD-R (CD Recordable).

2. Description of the Related Art

The CD is well known as a recording medium to record acousticinformation or the like. The CD has a lead-in area LIA where indexinformation of recorded information is recorded, a program area PA whereactual musical information is recorded, and a lead-out area LOAindicating the end of the program area PA, formed thereon in the namedorder from the inner periphery of the disk, as shown in FIG. 1(a). Thoseareas LIA, PA and LOA as a whole are called an information area. Asignal to be recorded is a digital signal modulated by EFM (Eight toFourteen Modulation), and includes a main code (main information) suchas musical information, and a sub code such as a time code (timeinformation). Index information called TOC (Table Of Contents) isrecorded in the lead-in area LIA, and the total number of recordedinformation pieces (e.g., the total number of musical pieces), the totalprogram time (e.g., the total playing time), etc. are recorded as a subcode also in that area LIA. Musical information or the like is recordedas a main code in the program area PA. A track number (TNO) indicatingthe number of each piece of recorded information (e.g., the musicnumber), the program time (P-TIME) from the beginning of the track, suchas the playing time of the music piece, the total program time (A-TIME)measured from the first track number (=1), such as the total playingtime, etc. are recorded in the Q channel of the sub code in the programarea PA. In the lead-out area LOA is recorded a lead-out code indicatingthe lead-out area.

In a CD player that plays back the above CD, when the CD is set, apickup is moved to a predetermined position (home position), a setupoperation is then performed to rotate the CD to make it ready forinformation reading therefrom, and TOC information is read from thelead-in area upon completion of the setup operation. In reading the TOCinformation, however, the TOC information may not be acquired due tosome scratches on the disk. In such a case, information in the programarea is to be reproduced without TOC information. To accomplish thisreproduction, conventionally, it is discriminated whether the disk is a"normal CD with TOC" or "normal CD without TOC" based on the result ofreading the TOC information, and the information on the discriminationresult is stored as disk discrimination information.

FIG. 2 shows a flowchart of a process for reading TOC information in theconventional CD player. It is seen from the flowchart thatconventionally, the information area is searched first for the lead-inarea for a given period of time (steps S51, S52 and S53). If the lead-inarea cannot be detected when the time is out, i.e., the TOC informationcannot be read out, it is considered that the disk is a "normal CDwithout TOC" and the information to that effect is stored (step S57).When the lead In area is detected, the TOC information is read until thereading is complete or the time is out (steps S54, S55 and S56). Whenthe time is out, or the TOC information cannot be read, the disk isconsidered as a "normal CD without TOC" and the information to thateffect is stored (step S57). When the reading is complete, on the otherhand, the disk is considered as a "normal CD with TOC" and theinformation to that effect is stored (step S58). The disk discriminationinformation thus acquired and stored will be used in later processessuch as information searching.

While a CD having the above-described recording format is a read-onlyrecording medium, an additionally recordable CD-R having the same formatas the CDs has been developed recently. This CD-R recording formatstandard is standardized into a so-called "Orange Book", and conforms tothe CD format standard (called a "red book"). The CD-R disks areclassified into the following three types as shown in FIG. 1(b) to FIG.1(d) depending on the recording status.

FIG. 1(b) shows a section of a blank or unrecorded CD-R disk where noinformation has been recorded yet. FIG. 1(c) shows a section of apartially recorded CD-R disk (hereinafter referred to as "PRD") whereinformation is partially written. FIG. 1(d) shows a section of afinalized CD-R disk for which recording is complete and which hasfinally been formatted in nearly the same format as CDs.

As illustrated in FIG. 1(b) to FIG. 1(d), the lead-in area LIA, programarea PA and lead-out area LOA are also formatted on each CD-R in thesame manner as that of CDs.

A pregroove is formed on the recording track of a CD-R, and it iswobbled by a frequency that is acquired through FM modulation of acarrier with data indicating the absolute time information (ATIP:Absolute Time In Pregroove). In a CD-R recording and playback apparatus,the tracking control and spindle control are performed according to thepregroove so that information is recorded on and read from a blank diskas well as a PRD. A PMA (Program Memory Area) as a temporary TOC area tostore the recording history of recorded information is provided on thePRD at the inner periphery side of an area I that is reserved for thelead-in area LIA as indicated in FIG. 1(c). In this PMA the followingthree types of information are recorded. The first information includesthe start and end addresses of information recorded in the program area,which are recorded in the same format as TOC information that isrecorded in the lead-in area. The second type is disk identificationinformation (optional) which may be 6-digit numeral information toidentify a disk as needed. The third type is skip command informationand skip release information, which are associated with a command toskip the recorded information piece (track) by piece or part of eachpiece (track) of the recorded information (time designatable in thelatter case) at the time of playing back the disk. The reason forrecording such information as temporary TOC in the PMA is that sinceinformation is writable in the remaining program area PA on the PRD, TOCinformation cannot be recorded in the lead-in area LIA until thefinalization of recording is instructed finally.

In a PRD, no information is written in an area I for the lead-in areaLIA and an area O for the lead-out area LOA. Therefore, those areasremain in a mirror-finished state. When a command for finalization isgiven, the CD-R recording apparatus records predetermined informationand TOC information recorded in the PMA as a sub code in the area I forthe lead-in area LIA, and records a predetermined lead-out codeindicating the lead-out area LOA in the area O for the lead-out area LOAin order to provide the same format as that of CDs at last. This allowsthe conventional CD player to play back the finalized CD-R.

While the conventional CD player is capable of playing back a finalizedCD-R, it cannot reproduce reproducible information from a PRD thoughthat information is stored in the program area PA. To describe indetail, it is so because of the following reasons. Although a PRD hasTOC information recorded in the PMA provided on the inner periphery sideof the lead-in area, the conventional CD player is equipped with nomechanism to access that PMA. In addition, the area I for the lead-inarea LIA and the area O for the lead-out area LOA remain mirror-finishedand the conventional CD player is not designed to perform the propercontrol on information reading from such areas so that runaway of theservo system may occur in reading information from those areas.

As a solution to this problem, like the CD-R recording and playbackapparatus, the CD player may be equipped with the mechanism to accessthe PMA and some means to read the pregroove and perform the trackingand spindle controls. The provision of such means only for the PRD isnot cost effective.

Prior to the reproduction of recorded information, the conventional CDplayer moves the pickup to the position corresponding to a predeterminedhome position on a CD in accordance with the recording format of the CDand performs a setup operation such as pull-in of a servo system. Thishome position is set near the boundary between the lead-in area LIA andprogram area PA for the conventional CD player.

However, the home position on the CD is likely to deviate depending onthe precision of the mechanism of the CD player and the eccentricity ofthe CD. The predetermined physical home position of the pickup may nottherefore correspond to the predetermined home position on the CD. Witha PRD set in the conventional CD player, since no information is yetrecorded in the area I for the lead-in area LIA which remainsmirror-finished, the setup operation cannot be carried out when thephysical home position of the pickup enters this area I. Even if thesetup operation is tried again (setup retry), the physical home positionof the pickup is very likely to enter the area I for the lead-in areaLIA again, making it unlikely to properly finish the setup operation.Even if some information has been recorded on the CD-R, it is consideredthat the disk is set with the back side facing the pickup, thusterminating the reproducing operation or rejecting that disk (firstproblem).

There is a demand for the development of a CD player which can reproduceinformation from the program area simply with alteration on the controlsystem for PRDs in order to widen the applicability of CD-Rs. Asmentioned earlier, the read-only CD and the PRD have different diskformats. Therefore, the conventional CD player cannot play back a PRD bythe same control as employed for CDs and needs different control. Withthe use of the above-described disk discrimination in the conventionalCD player that determines the type of the disk depending on whether ornot it has "TOC", the PRD is discriminated as a "normal CD without TOC"and this discrimination is insufficient to reproduce information fromthe program area of the PRD (second problem).

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide aCD player which overcomes the first problem, and which can thus performthe setup operation even when a partially recorded CD-R is set thereinand play back the CD-R.

It is another object of the present invention to provide a CD playerwhich overcomes the second problem, and which can thus properlydiscriminate a PRD, that is, a partially recorded, additionallyrecordable CD-R, and can execute the reproduction control for the PRD.

To achieve the foregoing objects, according to the first aspect of thepresent invention, there is provided a CD player for performing a setupoperation to set up a pickup and a servo system to reproduce informationrecorded on a CD, comprising setup control means for sequentiallyperforming the setup operation, starting from a first setup positionlocated at a position of the side of the innermost periphery of the CD,predetermined for the setup operation, until the setup operation iscomplete at any of n-th (n=2, 3, . . . ) setup positions lying outwardlyof the first setup position, and, if the setup operation is notcompleted even at an n-th setup position located at a position of theside of the outermost periphery of the CD, performing the setupoperation again at at least one setup position lying inwardly of then-th setup position.

According to the first aspect of the present invention, the setupcontrol means sequentially performs the setup operation, starting fromthe first setup position (e.g., a predetermined position near theboundary between the lead-in area and program area of a CD) located at aposition of the side of the innermost periphery of the CD, predeterminedfor the setup operation, until the setup operation is complete at any ofn-th (n=2, 3, . . . ) setup positions lying outwardly of the first setupposition, and, if the setup operation is not completed even at an n-thsetup position located at a position of the side of the outermostperiphery of the CD, performs the setup operation again at at least onesetup position lying inwardly of the n-th setup position. Even if therecording area is short as on a PRD having a short recording time or anytwo setup positions happen to lie outside the recording area due to theeccentricity of the disk or the like, therefore, the setup control meanscan complete the setup operation.

According to the second aspect of the present invention, there isprovided a CD player for discriminating a disk by control to detect thelead-in area and control to read TOC information, comprising diskdiscriminating means for discriminating a disk as a not finalized onewhen a mirror-finished portion is detected in the control to detect thelead-in area or when the lead-in area cannot be detected and the TOCinformation cannot be read.

When the lead-in area is detected after the setup operation and then TOCinformation is controllably read out, for example, the CD player of thesecond aspect of the present invention discriminates if the lead-in areais detected. At the same time, it is detected if the lead-in area ismirror-finished according to a predetermined decision routine in thecontrol to detect the lead-in area. The disk discriminating meansdiscriminates the disk to be played back as a not finalized one when amirror-finished portion is detected in the control to detect the lead-inarea. If the lead-in area cannot be detected within a predeterminedperiod of time and the TOC information cannot be read in the TOCinformation reading control, the disk discriminating means alsodiscriminates the disk to be played back as a not finalized one. Whenthe disk is discriminated as a not finalized one in the operation toplay back the disk, the proper control for that disk can be executed toplay back the disk.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1(a-d) are diagrams for explaining the recording formats ofvarious disks;

FIG. 2 is a flowchart of a disk discriminating routine in theconventional CD player;

FIG. 3 is a diagram illustrating the basic structure of a CD playerembodying the present invention;

FIG. 4 presents a flowchart illustrating the operation of a firstembodiment of the first aspect of the present invention;

FIG. 5 is a diagram (part 1) for explaining the operation of the firstembodiment of the first aspect of the present invention;

FIGS. 6(a-b) are diagram (part 2) for explaining the operation of thefirst embodiment of the first aspect of the present invention;

FIG. 7 presents a partial flowchart illustrating the operation of asecond embodiment of the first aspect of the present invention;

FIG. 8 is a diagram for explaining the operation of the secondembodiment of the first aspect of the present invention; and

FIG. 9 is a flowchart of a TOC reading routine including diskdiscriminating means of a first embodiment of the second aspect of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be describedreferring to FIGS. 3 through 8.

First Embodiments of The First Aspect of The Present Invention

FIG. 3 presents a block diagram showing the basic structure of a CDplayer to which the present invention is applied.

A CD (or a partially recorded or a finalized CD-R) 1 to be played backis placed on a turntable (not shown) of a CD player 100. A spindle motor2 rotates the CD1 based on a spindle servo control signal S_(sc) from aservo unit 3. A pickup 4 reads recorded data on the CD1 and outputs itas a playback RF signal S_(RF) to a preamplifier section 5. Thepreamplifier section 5 amplifies the playback RF signal S_(RF), andoutputs the amplified signal to a decoder unit 6. The preamplifiersection 5 also produces an error signal S_(ER) from the playback RFsignal S_(RF) and outputs it to the servo unit 3. The servo unit 3includes a first servo section 3A and a second servo section 3B. Thefirst servo section 3A produces a tracking error signal S_(TE) and afocusing error signal S_(FE) from the error signal S_(ER) and a controlsignal S_(CON) from a system controller 7 to execute tracking servo andfocusing servo for the pickup 4. The first servo section 3A alsoperforms carriage servo to drive a carriage 8 based on the controlsignal S_(CON) from the system controller 7 and the error signal S_(ER)from the preamplifier section 5. Near the carriage 8 is provided a homeposition detection switch 9, which detects the home position of thecarriage 8 and outputs a home position detection signal S_(HM) to thesystem controller 7. The decoder unit 6 includes an audio-data decodingsection 6A and a control-data decoding section 6B. The audio-datadecoding section 6A converts the received playback RF signal S_(RF) intoa binary signal, separates a frame sync pattern therefrom, demodulatesthe signal based on the EFM (Eight to Fourteen Modulation), performssignal processing, such as error correction, on the resultant signal,and outputs audio data D_(AD) to a D/A converter section 10. Theaudio-data decoding section 6A also outputs control data D_(CN) includedin a sub code to the control-data decoding section 6B. The decodingsection 6B decodes the control data DcN and outputs the resultant datato the system controller 7. At the same time, the decoder unit 6produces a spindle servo error signal S_(SE) from the input playback RFsignal S_(RF) and outputs it to the second servo section 3B. The secondservo section 3B serves as a spindle servo section. Based on the spindleservo error signal S_(SE) and control signal S_(CON), the second servosection 3B outputs the spindle servo control signal S_(SC) to thespindle motor 2 to rotate the spindle motor 2 at a predetermined speed.The D/A converter section 10 converts the input audio data D_(AD) intoan analog signal and outputs it as an audio output signal S_(OUT). Thesystem controller 7 performs the general control of the CD player 100based on the control data D_(CN) and an operation control signal from adisplay/operation section 11. The display/operation section 11 isequipped with a display section (not shown) to display various types ofinformation and inform a user of such information, and performs variousdisplays under the control of the system controller 7.

The recording format of CDs is described in detail below.

In the format of CDs that conforms to the CD format standard (generallycalled "Red Book"), the information area where a recording track isformed must comply with the following regulations.

1) The lead-in area LIA shall begin within a radius of 23 mm from thecenter of the disk.

2) The program area PA shall start from a point 25 mm radially from thecenter of the disk and shall end at a point 58 mm at most radially fromthe center of the disk.

3) The lead-out area LOA shall be 0.5 mm wide or wider in the radialdirection after the end of the program area PA.

It is apparent from the above that any CD has a track formed in an areabetween the radius of 23 mm and the radius of 25.5 mm, so that to invokefocus servo at the time of playing back a CD, a home position may be setin this area and a beam from the pickup may be irradiated on this homeposition to perform the setup operation.

Before the operational description of this embodiment, the setupoperation will be described.

1) Move Pickup to Initial Position

In the setup operation, first, the pickup is moved to the initialposition. For instance, if the home position is set so that the beamspot position is about 24 mm in radius from the center of the CD 1, thesystem controller 7 controls the first servo section 3A and drives thecarriage 8 to move the pickup 4 toward the inner periphery of the CD 1.As a result, the carriage 8 is moved to the position (initial position)where the beam spot from the pickup 4 comes closer to the center of theCD 1 than the predetermined home position (about 24 mm in radius). Thecarriage 8 is moved by radial servo that sets the relative speed of thebeam spot to the recording track in the radial direction constant.However, focus servo has not been applied yet in the above carriagemovement, so that the relative speed cannot be detected and the carriageis moved at the maximum speed allowable by a carriage motor (not shown).But the carriage 8 is controlled to move for a short period of time andthen be braked immediately thereafter, and to repeat this intermittentmovement until it reaches the initial position.

2) Move Pickup to Activation Position

Next, the pickup 4 is moved to the activation position. This movement isdone by moving the carriage 8 in the same manner as the movement to theinitial position but toward the outer periphery of the CD 1 this time.It is detected that the pickup 4 has reached the activation positionwhen the home position detection switch 9 is turned off, and then themovement to the activation position is terminated. Accordingly, theactivation position comes slightly outward of the home position.

3) Activate Semiconductor Laser

When the pickup 4 reaches the activation position, the system controller7 activates a semiconductor laser (not shown) in the pickup 4 and waitsfor the laser to be stable.

4) Activate Focus Servo

When the semiconductor laser becomes stable, the system controller 7activates the focus servo.

5) Rotate Disk

Then, the system controller 7 feeds a large constant current to thespindle motor 2 via the second servo section 3B of the servo unit 3 andaccelerates the rotation of the CD 1 to about 500 rpm nearly equal tothe rotational speed involved in accessing the inner periphery side ofthe CD 1.

6) Examine pull-in of Focus Servo

Next, the system controller 7 examines if the focus servo has beenpulled-in.

7) Activate Tracking Servo

When a completion of the pull-in of the focus servo is detected, thesystem controller 7 activates the tracking servo and carriage servo, andthen examines if both servos have completed pull-in.

8) Activate Sync Servo

After the tracking servo and carriage servo have completed pull-in, thesystem controller 7 switches the spindle servo to sync servo, whichthereafter controls the spindle motor 2 to make the rotating CD 1 havenearly the correct linear speed.

9) Lock PLL

Immediately after the sync servo is activated, the speed of the spindlemotor 2 may not be the correct linear speed.

Thus, the system controller 7 detects the frame sync in the reproducedsignal, and performs control based on the frame sync so that the speedof the spindle motor 2 comes within a range of several percent of thecorrect linear speed, and the PLL is locked in.

The setup operation is terminated after the above steps 1) to 9) areexecuted, and the CD player goes to the normal playback operation. Theabove sequence of steps is just one example of the setup operation, andis in no way restrictive.

Referring now to the operational flowchart of FIG. 4 and FIGS. 5 and 6,a description will be given of the setup routine for the CD player thatis executed by the system controller 7. In this case, it is assumed thata PRD is placed on the turntable and the blank disk flag BLF indicatingthat the disk may be a blank disk is set to "0".

First, the system controller 7 determines whether or not TOC informationhas already been read (step S1).

When the TOC information has not been read in step S1, the disk iscertainly a PRD, i.e., the disk is surely a PRD because the TOCinformation cannot be read, so that the routine goes to step S17. If theTOC information has been read in step S1, on the other hand, it isunknown if the disk is a PRD and the above-described setup operationwill be performed at a normal home position H₁ (see FIG. 5) in step S2.

Then, it is determined based on the home position detection signal ifthe setup has been carried out properly (step S3). When the proper setuphas been done, the setup routine will be terminated (step S19).

If the setup has not been done properly, the setup operation isperformed at a position outward of the normal home position or an outerhome position H₂ (see FIG. 5) (step S4).

Then, it is determined if the setup has been carried out properly at theouter home position H₂ (step S5). When the proper setup has been done,the setup routine will be terminated (step S19).

When the setup has not been carried out properly at the outer homeposition H₂, it is determined from the stored information whether or notthe setup has ever been executed for this disk (step S6). When it isfound that the setup has never been done for this disk, it is unknownthat the disk is a blank disk, so that the setup operation will beperformed again at the normal home position H₁ (step S7). The setupoperation is retried at the normal home position H₁ because of thefollowing reason. In the case where the recording time of the programarea PA is short and further the center D_(C) of the disk is shiftedfrom (or eccentric to) the rotational center S_(C) of the spindle motor2 by ΔC as shown in in FIG. 6(a), if the setup operation cannot be doneat the normal home position H₁ so that the setup operation is retried atthe outer home position H₂ after a predetermined period of time, thepickup 4 may be positioned beyond the recorded area of the program areaPA at the outer home position H₂ by the rotation of the disk while thesetup operation may be performed at the normal home position H₁, asindicated in FIG. 6(b).

If the setup has ever been executed for this disk, the disk is not ablank disk so that the routine goes to step S20.

Case A: The disk may be a blank disk

It is then determined if the setup has been carried out properly (stepS8). When the proper setup has been done, the setup routine will beterminated (step S19).

When the setup has not been done properly, the blank disk flag BLFindicating that the disk may be a blank disk is set to "1" (step S9) andthe setup routine enters a setup retry routine (steps S10 through S12).In this setup retry routine, it is determined how many times the retryhas been done (step S10); and if it is going to be an even-numberedretry, the setup operation is performed at the normal home position H₁(step S11); or if it is going to be an odd-numbered retry, the setupoperation is performed at the outer home position H₂ (step S12).

As it is the first, odd-numbered retry in this case, the setup operationis performed at the outer home position H₂ (step S12).

Then, it is determined if the setup has been carried out properly at thehome position (either the normal home position H₁ or outer home positionH₂) (step S13). When the proper setup has been done, the setup routinewill be terminated (step S22).

When it is determined in step S13 that the setup has not been carriedout properly at that home position, it is determined if the blank diskflag BLF indicates "1" (step S14).

As the blank disk flag BLF=1 in this case, the flag BLF is reset to "0"(step S15) and a blank disk process such as stopping the operation orrejecting the disk is executed (step S16) before the routine isterminated (step S22).

Case B: There is no possibility that the disk is a blank disk

When the disk is not a blank disk, it is determined if the setup retryhas already been done six times in the setup retry routine (step S20).As no setup retry has been done yet in this case, the process goes tothe setup retry routine. If the setup retry has already been done sixtimes, on the other hand, it is considered that the setup is disabledand the operation will be terminated (step S21).

In this setup retry routine, it is determined how many times the retryhas been done (step S10); and if it is going to be an even-numberedretry, the setup operation is performed at the normal home position H₁(step S11); or if it is going to be an odd-numbered retry, the setupoperation is performed at the outer home position H₂ (step S12).

As it is the first, odd-numbered retry in this case, the setup operationis performed at the outer home position H₂ (step S12).

Then, it is determined if the setup has been carried out properly at thehome position (step S13). When the setup has been done properly, thesetup routine will be terminated (step S22).

When it is determined in step S13 that the setup has not been carriedout properly at that home position, it is determined if the blank diskflag BLF indicates "1" (step S14).

As the blank disk flag BLF=0 in this case, the routine goes to step S20to determine whether or not the setup retry has already been done sixtimes (step S20). As the setup retry has been done once in this case,the process goes again to the setup retry routine. In this setup retryroutine, it is determined how many times the retry has been done. As itis the second, even-numbered retry, the setup operation is performed atthe normal home position H₁ (step S11). Then, it is determined if thesetup has been carried out properly at the home position (step S13).When the setup has been done properly, the setup routine will beterminated (step S22).

When it is determined in step S13 that the setup has not been carriedout properly at that home position, the sequence of steps S10 to S14 andS20 is likewise executed to perform the setup operation until the sixthsetup retry is made. In the setup retry routine, therefore, the setupoperation at the outer home position H₂ and the setup operation at thenormal home position H₁ are executed alternately, three times at thenormal home position H₁ and three times at the outer home position H₂ ata maximum. When the setup is not successful in any of the six setupoperations, it is considered that the setup is disabled and theoperation will be terminated (step S21).

In short, when a disk other than a blank disk is set in the CD player,the setup operation at the outer home position H₂ and the setupoperation at the normal home position H₁ are alternately performed inthe setup retry routine, so that it is very likely to accomplish thesetup operation even if the set disk is a CD or CD-R, increasing thepossibility to play back a PRD.

Second Embodiment of The First Aspect of The Present Invention

A second embodiment of this invention will be described referring toFIGS. 7 and 8. This embodiment differs from the first embodiment in thata second outer home position H₃ located outward of the outer homeposition H₂, as well as the aforementioned normal home position H₁ andouter home position H₂, is provided as a home position at which thesetup operation is performed.

FIG. 7 illustrates an operational flowchart of the part which differsfrom the operational flowchart shown in FIG. 4.

The operational flowchart in FIG. 7 illustrates a setup retry processthat is executed instead of the setup retry routine of steps S10 to S12in FIG. 4. According to this embodiment, as illustrated in FIG. 8, thesetup operation is executed, first at the normal home position H₁, thenat the outer home position H₂, then at the second outer home positionH₃, then again at the normal home position H₁, and so forth. It isapparent from the diagrams that the first and fourth setup operationsare performed at the normal home position H₁ (step S31), the second andfifth setup operations are performed at the outer home position H₂ (stepS33), and the third and sixth setup operations are performed at thesecond outer home position H₃ (step S34). Even if a PRD is set, it ispossible to accomplish the setup operation more surely, furtherincreasing the possibility to play back the PRD.

According to the second embodiment, the setup operation is carried out,first at the normal home position H₁, then at the outer home positionH₂, then at the second outer home position H₃, then again at the normalhome position H₁, and so forth. However, the setup operation may beexecuted in an arbitrary order. Further, one or more home positions maybe provided further outward of the second home position H₃ so that thesetup operation can be executed, first at the normal home position H₁,then at the outer home position H₂, . . . , then at the outermost homeposition H_(n), then again at the normal home position H₁, and so forth.

Although the setup operation is performed, first at the innermost setupposition, then at the second innermost setup position, . . . , then atthe outermost setup position, then again at the innermost setupposition, and so forth in the second embodiment, the setup operation maybe performed, first at the outermost setup position, then sequentiallyat inner setup positions. Further, the setup operation may be performed,first at the innermost setup position, then sequentially at outer setuppositions up to the outermost setup position, then at those of the innersetup positions which are properly selected.

Although the number of setup retry operations is set to six in bothembodiments described above, the setup retry may be performed anarbitrary number of times equal to or greater than two.

According to the first aspect of the present invention, as describedabove, the setup control means sequentially performs the setupoperation, starting from the first setup position (e.g., a predeterminedposition near the boundary between the lead-in area and program area ofa CD) located at a position of the side of the innermost periphery ofthe CD, predetermined for the setup operation, until the setup operationis complete at any of n-th (n=2, 3, . . . ) setup positions lyingoutwardly of the first setup position, and, if the setup operation isnot completed even at an n-th setup position located at a position ofthe side of the outermost periphery of the CD, performs the setupoperation again at at least one setup position lying inwardly of then-th setup position. Even if the recording area is short as on a PRDhaving a short recording time or either one of the two setup positionsmay not have the recording area due to the eccentricity of the disk orthe like, therefore, it is possible to surely complete the setupoperation. Even when a partially recorded CD-R (PRD) is set in the CDplayer, it is possible to surely complete the setup operation and thusplay back the disk.

A preferred embodiment of the second aspect of the present inventionwill be described below.

Referring to FIG. 3, when the disk 1 is set, the system controller 7first drives the carriage 8 as a servo mechanism via the servo unit 3 tomove the pickup 4 to the home position set near the innermost portion ofthe program area. Then, the system controller 7 performs a setupoperation to drive the spindle motor 2 and sequentially activate theindividual servos, making the CD player ready for informationreproduction. If there is a scratch at that position on the disk whichcorresponds to the home position, or the home position comes on themirror-finished portion of the PRD, the setup may not be carried out. Inthis case, the pickup 4 is moved outward of the home position and thesetup is tried again as done in the previous embodiments, allowing theinformation at the innermost portion of the program area to bereproduced.

When the setup is complete, a process to read TOC information isperformed next. This process of reading the TOC information includes aprocess serving as the disk discriminating means of the presentinvention. That is, it is discriminated whether the disk is a "normal CDwith TOC", "normal CD without TOC" or "PRD" that is a partiallyrecorded, additionally recordable disk, based on the result of readingthe TOC information, and information on the discrimination result isstored as disk discrimination information. Thereafter, when playback isinstructed from the display/operation section 11, reproduction of therecorded information in the program area is controlled according to thedisk discrimination information.

FIG. 9 illustrates a flowchart of a process for reading TOC information(TOC reading), which includes the disk discriminating means of thepresent invention. The TOC reading process of this embodiment will beexplained referring to this flowchart.

First, the system controller 7 searches for the lead-in area (step S71).If the reproduced disk is a PRD, the lead-in area is mirror-finished sothat the pickup 4 moves on the mirror-finished portion and no servo isenabled, causing runaway of the servo system. At this time, whendetecting the runaway of the servo system, the system controller 7 stopsthe spindle motor 2 and executes the setup operation to search for thelead-in area again. In this embodiment, when searching for the lead-inarea results in three runaways of the servo system, it is discriminatedthat the lead-in area is mirror-finished and the disk is a PRD, and"PRD" is stored as the disk discrimination information (step S72). Inthis case, the lead-in area is considered as mirror-finished whenrunaway of the servo system occurs three times in the process ofdetecting the mirror-finished portion. But as the number of the runawaysis determined in consideration of scratches or vibration of the disk,any number can be selected as long as the mirror-finished state issurely detected.

Even if the reproduced disk 1 is a PRD having a mirror-finished lead-inarea, when the tracking control of the pickup 4 uses three spot beams,the pickup 4 does not move to the mirror-finished portion, causing norunaway of the servo system. But the lead-in area cannot be searched inthis case too, so that timeout occurs. Further, even with a normal CD,if the lead-in area cannot be detected due to scratches or the like onthe CD, timeout also occurs (steps S73 and S74). When the lead-in areacannot be detected and timeout occurs, reading TOC information is thenconducted (step S75). If the disk is a PRD, the T0C information cannotbe read as a matter of course, causing timeout. In this case, therefore,the disk is discriminated as a PRD and "PRD" is stored as the diskdiscrimination information (steps S76, S77 and S78). When reading theTOC information is possible and is completed, the disk is discriminatedas a normal CD from which the TOC information can be read, and "normalCD with TOC" is stored as the disk discrimination information (stepS79).

When the lead-in area is detected in step S73, the routine goes to aprocess of reading TOC information as done in the prior art. If thereading is completed, the disk is discriminated as a "normal CD withTOC", or if the reading cannot be accomplished before the time is out,the disk is discriminated as a "normal CD without TOC", and thediscrimination result is stored as the disk discrimination informationin each case (steps S80, S81, S82, S83 and S84).

Table 1 below shows the correlation between the conditions and theresults of the disk discrimination.

As shown in Table 1, in the disk discrimination of this embodiment, whena normal CD is detected and the lead-in area is detected asmirror-finished, or the lead-in area cannot be detected and TOCinformation cannot be read, the reproduced disk is discriminated as aPRD and the discrimination result is stored accordingly. It is thereforepossible to perform the playback control according to the reproduceddisk later, referring to the disk discrimination information. This makesit possible to play back even a PRD having no TOC information and amirror-finished lead-in area to reproduce information recorded in theprogram area.

                  TABLE 1                                                         ______________________________________                                        Lead-in Area TOC Reading                                                                              Results                                               ______________________________________                                        (1)  detected    readable   normal CD with TOC                                (2)  detected    timeout    normal CD without TOC                             (3)  timeout     readable   normal CD with TOC                                (4)  timeout     timeout    PRD                                               (5)  mirror-finished                                                                           --         PRD                                                    portion detected                                                         ______________________________________                                    

As described above, the CD player according to the second aspect of thepresent invention can discriminate a not finalized disk and can performlater playback control according to the disk in use, ensuring thereproduction of recorded information from the additionally recordabledisk.

What is claimed is:
 1. A determination method for determining whether ornot a disk, positioned for playback in a CD player, is a partiallyrecorded CD in which recording or formatting have not been finalized,said method comprising the steps of:searching for a lead-in area of thedisk using a pickup of the CD player to scan across a surface of thedisk a predetermined number of times; in response to said searchingstep, interpreting a predetermined number of runaways of a servo systemof the CD player as an affirmative detection of a mirror-finishedportion of the disk; and determining from the affirmative detection ofthe mirror-finished portion that the disk is a partially-recorded CD. 2.The determination method as claimed in claim 1, whereinsaid searchingstep comprises three scans across the surface of the disk; and saidinterpreting step comprises counting runaways of the servo system inresponse to said searching step, and interpreting a count of threerunaways of the servo system as the affirmative detection of themirror-finished portion of the disk.
 3. A determination method fordetermining which type of disk is positioned for playback in a CDplayer, wherein the disk types include a recordable CD and apre-recorded disk, said method comprising the steps of:searching for alead-in area of the disk using a pickup of the CD player to scan acrossa surface of the disk a predetermined number of times; in response tosaid searching step, counting runaways of a servo system of the CDplayer, and comparing the counted runaways to a predetermined number ofrunaways, wherein a first comparison result constitutes an affirmativedetection of a mirror-finished portion of the disk, and a secondcomparison result constitutes a failure to detect the mirror-finishedportion of the disk; determining from the affirmative detection of themirror-finished portion that the disk is a recordable CD; in response tothe failure to detect the mirror-finished portion, conducting, for afirst predetermined period of time, a further search for the lead-inarea of the disk using the pickup of the CD player; if, in saidconducting step, the lead-in area is detected during the firstpredetermined period of time, determining that the disk is apre-recorded disk; if, in said conducting step, no lead-in area isdetected during the first predetermined period of time, performing, fora second predetermined period of time, a reading step to read table ofcontents information from the disk; if, in said reading step, the tableof contents information is successfully read during the secondpredetermined period of time, determining that the disk is apre-recorded disk; and if, in said reading step, no table of contentsinformation is read during the second predetermined period of time,determining that the disk is a recordable CD.
 4. The determinationmethod according to claim 3, wherein said step of determining that thedisk is a pre-recorded disk if the lead-in area is detected during thefirst predetermined period of time comprises the steps of:performing,for a third predetermined period of time, a further reading step to readtable of contents information from the disk; if, in said further readingstep, the table of contents information is successfully read during thethird predetermined period of time, determining that the disk is apre-recorded disk with table of contents information; and if, in saidfurther reading step, no table of contents information is read duringthe third predetermined period of time, determining that the disk is apre-recorded disk without table of contents information.
 5. Thedetermination method according to claim 3, further comprising the stepsof:storing information representative of the type of disk determined asdisk discrimination information; and controlling playback of the diskbased on the stored disk discrimination information.
 6. A CD playercapable of discriminating between recordable and pre-recorded CDs,comprising:a carriage provided with a pickup for reading a diskpositioned for playback in the CD player; a servo unit connected to saidcarriage over a signal path, for driving said carriage; a systemcontroller connected to said carriage and said servo unit overrespective signal paths in a feedback arrangement, wherein said systemcontroller outputs output signals to said servo unit and receives inputsignals from said carriage; wherein said system controllera) controlssaid servo unit, via first ones of the output signals, to move saidcarriage and pickup across a surface of the disk a predetermined numberof times and to search for a lead-in area of the disk; b) countsrunaways of said servo system via first ones of the input signals; c)compares the counted runaways to a predetermined number of runawaysstored in said system controller; d) stores disk discriminationinformation identifying the disk as a recordable CD if the comparisonyields a first comparison result; e) controls said servo unit, viasecond ones of the output signals, to move said carriage and pickupacross the surface of the disk for a first predetermined amount of timeand to search again for the lead-in area of the disk if the comparisonyields a second comparison result; f) receives second ones of the inputsignals indicating whether or not the lead-in area is detected duringthe first predetermined amount of time; g) stores disk discriminationinformation identifying the disk as a pre-recorded CD if the lead-inarea is detected within the first predetermined amount of time; h)controls said servo unit, via third ones of the output signals, to movesaid carriage and pickup across the surface of the disk for a secondpredetermined amount of time and to read for table of contentsinformation stored on the disk if the lead-in area fails to be detectedwithin the first predetermined amount of time; i) receives third ones ofthe input signals indicating whether or not the table of contentsinformation is detected during the second predetermined amount of time;j) stores disk discrimination information identifying the disk as apre-recorded CD if the table of contents information is detected withinthe second predetermined amount of time; and k) stores diskdiscrimination information identifying the disk as a recordable CD ifthe table of contents information fails to be detected within the secondpredetermined amount of time.